VI THE YELLOW-WINGED SPHEX 91 



the Sphegidse in one colony on whom I cared to 

 experiment, I could not but perplex myself over it. 

 " Does then the insect obey a fixed tendency which 

 circumstances cannot modify ? " I asked myself. 

 " Are its actions all done by rule, and is it unable to 

 acquire the least experience from its own proceed- 

 ings?" Later observations modified this too absolute 

 judgment. 



The following year, at the proper time, I visited 

 the same spot. The new generation had inherited 

 for their burrows the place chosen by the preceding 

 ones ; it had also faithfully inherited their tactics, for 

 the cricket experiment gave the same results. Such 

 as were the Sphegidae of the past year such are 

 those of the present one, equally persistent in a 

 fruitless attempt. My error grew confirmed until 

 good luck brought me to another colony in a 

 different place. I renewed my experiments. After 

 two or three trials with the old, well-known result, 

 the Sphex got astride of the cricket, seized its 

 antennae with her mandibles, and dragged it at 

 once into the burrow. Who looked a fool then ? 

 The experimenter baffled by the clever Hymenopteron. 

 At the other holes her neighbours, some sooner, 

 some later, found me out, and went down with their 

 prey instead of persisting in leaving it on the threshold 

 to seize it later. What is the meaning of this ? 

 This colony, descended from another stock, for sons 

 return to the spot selected by their forefathers, is 

 cleverer than the one observed last year. Craft is 

 inherited ; there are sharper-witted tribes and duller 

 ones, apparently according to the faculties of their 

 forefathers. With Sphegidae, as with us, the kind 



